Trisazo dyes



United States Patent "ice patented $32 .1;

v;1 a v 2 Example 1 3,028,376 15.2 g. 5-nitro-2-amino toluene are diazot-ised as usual TRIS AZO DYES with 150 g. water, 35 g.v hydrochloric acid (density 1.17)

argeted reassess? d dddddd dddddd 1 d dddddd d dd d dddd N Drawing, Filed APB 1 1960, s 22,121 5 and keeping the temperature at 0 C.; the diam-compound Claims riorit ,a li ati n Italy Apr, 16, 1959 obtained is introduced into'a solution consisting of 15 g.

1 Claim. (Cl. 260-169) a-naphthylamine, 15 g. hydrochloric acid and 350 g.

d water; thereafter, a 50% sodium acetate (crystals) solu- An ob ect of the present invention is to provide certain dtion is gradually added until the mass gives a negative dyes, insoluble in Water, having The following reaction in the presence of the Congo red indicator. The

geneTal Formula A nitro-amino-azo-dye obtained is filtered and washed; it is CHa then dispersed in 300 g. water, alkalinized with ammonia and treated at 80 C. with about 14 g. sodium sulfide; the

O diamino-azo dye formed is filtered, washed and recrystal- 15 lized from 70% alcohol (melting point 167 C.).

13.8 g. (4-amino-2-methyl) 1-azo-4 l-naphthylamine thus obtained are suspended in 300 g. water, 35 g. conc. where X is selected from the group consisting of hydroxy hYdI ChI I C acid and are diazotised with 7 g. sodium and disubstituted amino groups and Ar is selected from nitrite in g. W r While k p ng the temperature at the group consisting of .phenyl and naphthyl groups, 20 between 0 and 5 C. by careful ice addition.

Th dyes f th above mentioned general F l A The bis-diazo-azo compound obtained is carefully added to a solution of 15.5 g. fi-naphthol in 200 g. water, 14 g. sodium hydroxide solution (36 B.) and 35 g. 30% ammonia solution; at the end of the coupling the trisazo-dye obtained is filtered, washed until it is neutral and dried; after grinding it consists of a dark powder having the formula:

are suitable for direct dyeing of polyolefinic materials by simple application at the boiling temperature of the dyeing bath.

Among the dyes of said general Formula A, the following dyes have shown to be particularly suitable for this dyeing of polypropylene and polyethylene materials:

on CH3 on 0H (13H: OH N=NC N=N N=N N: 8

(melting point 185 C.).

CH3 CH3 CH3 on, I

N N= N==N -N=NNo1n 0&3 JJHB The compounds of general Formula A are obtained By chromatography (eluent organic portion of the mixby diazotising in the presence of a strong acid, with soture butanol: acetic acid: water=4:1:5) a uniform violet dium nitrite one mol of a diamino azo compound of the spot is observed which turns neither with a hydrochloric type; acid nor with a sodium hydroxide solution.

CH3 R1 R Example 2 NON=N KN 5 13.8 g. (4-ammo-2-methyl) 1-azo-4 1-naphthylamine, R obtained as described in the preceding example, are diazotised as described and are then added to a solution of wher in R n 1 each represents hydrogen, y 14.5 g. N,N-dimethyl-m-toluidine in 200 g. water and P g in the p e Of a Strong base the bis'diazo'azo g. conc. hydrochloric acid (density 1.17); immediately Compound formed Wlth a compound of the type: 55 thereafter a 50% aqueous sodium acetate solution is added H ATX until there is no acid reaction with Congo red indicator. wherein Ar and X have the above mentioned meaning. The tris-azo dye thus formed is filtered, washed to neu- The following examples will further illustrate my intrali ty and dried; it consists of a dark-brown powder havvention however without limiting its scope. (All parts ing the following formula:

CH3 CH3 CH3 CH8 7 CH3 N N=N N=N N=N N\ C I OH;

are by weight unless otherwise indicated.) (melting point C.).

3 4 By paper chromatography a uniform violaceous red Having thus described my invention, what I desire to spot is observed which turns to blue with a hydrochloric secure and to claim by Letters Patent is: acid solution and remains unaltered with a sodium hy- The trisazo dye, insoluble in water, having the fordroxide solution. mula:

References Cited in the file of this patent UNITED STATES PATENTS 2,090,938 Conrad Aug. 24, 1937 FOREIGN PATENTS 80,421 Germany Dec. 17, 1891 84,289 Germany Dec. 16, 1894 277 Great Britain 1892 

